1. Field of the Invention
The present invention relates to an analog/digital color video apparatus and method for adjusting attributes of a color image contained in an analog video signal and a digital video signal, and visually displaying an attribute-adjusted video signal through a display, and more particularly, to an analog/digital color video apparatus and method for visually displaying an attribute-adjusted video signal through a flat type display.
2. Description of the Related Art
A conventional color video apparatus employs a flat type display to provide a high quality of image. Flat type displays such as a plasma display and a liquid crystal display use a digitized video signal as an input signal.
FIG. 1 is a block diagram showing the structure of a conventional analog/digital TV using a flat type display and which is compatible with both a digital signal and an analog signal. The conventional analog/digital TV comprises a first attribute adjust portion 10 for receiving an analog video signal and adjusting attributes of the received analog video signal, a second attribute adjust portion 20 for receiving a digital video signal and adjusting attributes of the received digital video signal, a switch 30, an analog-to-digital (A/D) converter 40 and a flat type display 50. For convenience of explanation, it is assumed that the analog video signal received by the first attribute adjust portion 10 is a color video signal in accordance with an NTSC (National Television System Committee) standard, and the digital video signal received by the second attribute adjust portion 20 is an HDTV (High Definition Television) video signal which is obtained through a demultiplexing and decoding process.
The first attribute adjust portion 10 receives an analog video signal and adjusts attributes of the received analog video signal. A chroma processor 11 in the first attribute adjust portion 10 generates a luminance signal Y, a first color difference signal R-Y and a second color difference signal B-Y from the received analog video signal. A first matrix circuit 13 generates color signals R, G and B from the luminance signal Y, the first color difference signal R-Y and the second color difference signal B-Y, using a predetermined matrix equation. A first attribute adjuster 15 receives and processes the color signals R, G and B according to a attribute control command input from a control panel 300 by a user and controls attributes such as sharpness, contrast, tint and brightness to then output the attribute-adjusted color signals R, G and B to the switch 30. The second attribute adjust portion 20 receives a demultiplexed and decoded digital video signal and adjusts the attributes of the received digital video signal. A digital-to-analog (D/A) converter 21 in the second attribute adjust portion 20 converts the received digital video signal into an analog signal. A second matrix circuit 23 generates color signals R, G and B from the output signal of the D/A converter 21, using a predetermined matrix equation. A second attribute adjuster 25 processes the color signals R, G and B according to attribute control command input from a control panel 300 by a user and adjusts attributes such as sharpness, contrast, tint and brightness to then output the attribute-adjusted color signals R, G and B to the switch 30. The switch 30 outputs the color signals R, G and B received from the first attribute adjuster 15 or the second attribute adjuster 25 to the A/D converter 40, according to a display mode select command input from the control panel 300 by a user. The A/D converter digitizes the color signals R, G and B received from the switch 30. The flat type display 50 combines images contained in the digitalized color signals R, G and B and visually displays the combined color image thereon.
The analog/digital TV of FIG. 1 converts a digital video signal into an analog signal in order to adjust the attributes of the digital video signal, and then converts the analog-converted signal back to a digital signal for the flat type display 50 which uses the digital signal as an input signal. However, the analog/digital TV of FIG. 1 generates quantization noise which is caused by the A/D conversion process. The quantization noise deteriorates the quality of a color image displayed on the flat type display 50.